In 3rd Generation Partnership Project (3GPP) long-term evolution (LTE) Release 10 (March 2011), which may also be referred to as LTE-Advanced (LTE-A), heterogeneous networks (HetNets) are relied upon to provide high-throughput communications. HetNets may include cells of different power class, e.g., macro, pico, or femto, and access class, e.g., open or closed-subscriber group (CSG). To accommodate for lack of intercell interference coordination (ICIC) control signaling in 3GPP LTE Release 8 (September 2009), multicarrier operation with cross-carrier scheduling was provided. This would allow for the control information applicable to a subframe of a first component carrier, being transmitted in the corresponding subframe of another component carrier that was deemed more reliable. A single subframe cross-carrier scheduling operation is facilitated by use of a carrier identification field (CIF) of UE dedicated downlink control information (DCI) to provide improved control reliability and enable enhanced ICIC (eICIC) for HetNets.
In 3GPP LTE Release 11, each component carrier may have its own time-division duplexing (TDD) uplink-downlink (UL-DL) configuration. However, aggregation of carriers with different TDD UL-DL configurations may complicate cross-carrier scheduling.